Front module for a motor vehicle

ABSTRACT

The invention relates to a front module for a motor vehicle, wherein the front module is in one piece and is composed exclusively of plastic.

RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.13/154,620, entitled “FRONT MODULE FOR A MOTOR VEHICLE,” filed on Jun.7, 2011 which claims priority to German Patent Application # DE10 2010029 787.9 filed on Jun. 8, 2010 and both are incorporated herein as iffully set forth.

FIELD OF THE INVENTION

The invention relates to a front module for a motor vehicle and to amethod for producing a front module.

BACKGROUND OF THE INVENTION

Generally known from the prior art are front modules for motor vehicles,which front modules are composed entirely of metal. Such front moduleshave generally been credited with the advantage of having highmechanical stability. A disadvantage of such front modules is howeverthe high weight on account of the use of metal. Furthermore, such frontmodules must for example additionally be provided, in a complex manner,with corrosion protection, which increases the production costs ofcorresponding front modules.

Also known from the prior art, for example from EP 1 612 024 A1, arecomposite components having a carrier component and a covering componentcomposed of plastic and having arranged between said components areinforcement component composed of metal.

BRIEF SUMMARY OF THE INVENTION

In contrast, the invention is based on the object of providing a frontmodule for a motor vehicle and also a method for producing a frontmodule.

The objects on which the invention is based are achieved in each case bymeans of the features of the independent patent claims. Preferredembodiments of the invention are specified in the dependent claims.

A front module for a motor vehicle is specified, wherein the frontmodule is in one piece and is composed exclusively of plastic. Here, usemust be made of a high-strength plastic, wherein high mechanicalstability of the front module is ensured on account of its being in onepiece. Because only plastic is used, it is for example possible toprovide any desired shapes and radii of the front module. Complexlacquering for the purpose of providing corrosion protection is likewisedispensed with. Furthermore, a corresponding front module has asignificantly lower inherent weight than a front module whichadditionally has metal. In this way, it is ultimately possible for theoverall weight of a vehicle to be reduced, which firstly lowers theenergy consumption of the vehicle and secondly results in higheracceleration values of said vehicle for the same drive power.

According to one embodiment of the invention, the front module has atrapezoidal shape with two horizontal support elements which are spacedapart from one another and two vertical support elements which arespaced apart from one another, wherein at least two of the supportelements are connected to one another by transverse struts. It ispointed out that, in the invention, the expression “trapezoidal” shouldnot be understood to mean a mathematically exact trapezoidal shape. Saidexpression should rather be understood to mean that the front module iscomposed substantially of four sides, wherein said sides, similarly tothose of a trapezium, are correspondingly aligned parallel to orinclined with respect to one another. This therefore however alsoincludes embodiments which have, for example with regard to one of saidsides, a significantly elongated V-shape or the like.

It is also pointed out that the expressions “horizontal” and “vertical”serve merely for general definition and do not restrict the alignment ofthe support elements, for example in relation to a vehicle body orgenerally in relation to a front module.

The use of transverse struts has the advantage that forces acting on theindividual support elements can be distributed in an efficient mannerover the entire front module. The mechanical stability of the frontmodule is significantly increased in this way.

According to one embodiment of the invention, the upper horizontalsupport element is connected by the transverse struts to the verticalsupport element or to the lower horizontal support element. This has theadvantage that normally high forces acting on the upper horizontalsupport element can be dissipated effectively over the entire frontmodule. In this way, the stability of the upper horizontal carrierelement need not imperatively be so high that forces acting on saidsupport element can correspondingly be dissipated to the verticalsupport elements. Although the total mass of the front module isincreased as a result of the introduction of the transverse struts, thetotal weight can however be reduced overall in turn as a result of theweight saving on account of the fact that the horizontal upper supportelement can be formed with lower stability.

According to a further embodiment of the invention, the support elementsare composed of a first plastic and the transverse struts are composedof a second plastic. Here, the first plastic is significantly lessstrong than the second plastic. This has numerous advantages.

Firstly, this yields a significant cost saving, because high-strengthand expensive plastics are used only where correspondingly high forcesneed to be conducted. As already mentioned above, forces acting inparticular on the upper horizontal support element are dissipated viathe transverse struts to the front module, such that it is adequate toensure particularly high stability and stiffness of the transversestruts. A further advantage is attained if the first plastic is aplastic which can be deformed in the event of a collision of a personagainst the front module. In other words, the use of two plastics ofdifferent hardness can therefore serve to provide pedestrian protection.

For example, it may be specified in this regard that, above a collisionspeed of 30 kilometres per hour of a person against the front module, adeformation of the latter occurs such that, in this way, the collisionenergy is reduced and furthermore the risk of injury for certain typesof injury decreases. In particular, it may be provided for this purposethat the upper horizontal support element is designed especially toprovide such pedestrian protection. That is to say, if a pedestriancollides with the engine hood arranged thereabove, the collision energycan be dissipated by the correspondingly regulated deformation of theupper horizontal support element.

According to a further embodiment of the invention, at least one of thesupport elements has at least a first and a second section, wherein thefirst section is composed of the first plastic and the second section iscomposed of the second plastic. In this way, local sections of the frontmodule can be mechanically reinforced. In this way, it is possible forexample to make allowance for the fact that forces can act on differentsections of the front module in a particularly significant way.

The front module has for example longitudinal support plates, preferablylikewise produced from plastic and integrally connected to the frontmodule. Said longitudinal support plates are arranged on the verticalsupport elements and are provided for fastening the front module to avehicle body. If in particular the longitudinal support plates are nowarranged on the vertical support elements at the level of the connectionpoints between the respective vertical support elements and thetransverse struts, a transmission of force from the front module to thevehicle body takes place to a high degree via said longitudinal supportplates. If, therefore, the longitudinal support plates and also theregions of the connection points of the respective vertical supportelements and the longitudinal support plates are now composed of thesecond plastic, it is ensured that no deformation of the front moduleoccurs at the stated points on account of the high forces acting. Inother words, high strength of the front module is ensured in this way.

It may thus be summarized that, in such an embodiment, the entire frontmodule is monolithic, that is to say in one piece, and is composedexclusively of plastic. Here, said front module notionally comprisesboth the horizontal and vertical support elements and also thetransverse struts and the longitudinal support plates. Such a frontmodule may be produced for example in a two-component injection-mouldingprocess in substantially two working steps, as a result of which a frontmodule can be produced in a cost-effective way. Welding and othermethods for connecting individual elements of the front module to oneanother are therefore dispensed with.

In this connection, it is also pointed out that the present invention isnot restricted to the use of only two plastics. It is also possible formore than two types of plastics to be used. For example, the horizontalsupport elements may be produced from a different plastic material thanthe vertical support elements. The longitudinal support plates may alsohave a different plastic material, which makes particular allowance forthe high forces acting on the longitudinal support plates.

According to a further embodiment of the invention, the second plasticis encapsulated by injection moulding by the first plastic. Here,“encapsulated by injection moulding” should not be understoodrestrictively to mean that the second plastic is completely enveloped bythe first plastic. It is also possible in principle in this regard forthe second plastic to be partially surrounded by the first plastic. Thishas the advantage that, similarly to the steel reinforcement in aconcrete wall, use can be made both of the mechanical properties of thefirst plastic and also those of the second plastic. For example, if onaccount of the high mechanical stability the second plastic is morebrittle and can be subjected only insufficiently to bending loads, it ispossible by means of the combination with the first plastic and thelower mechanical stiffness thereof to profit from the fact that, as aresult of the combination, an element is produced which has excellentmechanical properties both under compressive loading and also underbending loading. The overall stability of a correspondingly producedfront module is thereby significantly increased.

According to a further embodiment of the invention, the front modulealso has a receptacle for a lock for a bonnet of a motor vehicle,wherein the receptacle is constructed on the upper horizontal supportelement. The second section between the connection points of thetransverse struts to the upper horizontal support element may forexample serve for this purpose. In general, at least one of the supportelements has at least a first and a second section, wherein the firstsection is composed of the first plastic and the second section iscomposed of the second plastic.

The connection of a receptacle for a lock for a bonnet of a motorvehicle to the upper horizontal support element has the advantage thatforces acting on the front module in particular as a result of theclosure of an engine hood can be absorbed and distributed over the frontmodule as a whole in an effective manner. Here, if parts of the frontmodule additionally serve for pedestrian protection, the correspondingregion of the upper horizontal support element may be designed suchthat, as described above, corresponding impact energy can be dissipatedfrom the bonnet to the front module, and energy dissipationsimultaneously takes place.

In a further aspect, the invention relates to a method for producing afront module as described above by means of a two-componentinjection-moulding process, wherein the method has the following steps:

-   -   a) providing an injection-moulding device having a first and a        second cavity,    -   b) injecting the second plastic into the first cavity in order        to obtain an injection-moulded part,    -   c) transferring the injection-moulded part into the second        cavity,    -   d) injecting the second plastic into the first cavity in order        to obtain a further injection-moulded part, and injecting the        first plastic into the second cavity in order to obtain the        front module,    -   e) withdrawing the front module from the second cavity, and        repeating steps c-e.

Such a process yields the advantage that corresponding front modules canbe produced in a continuous manner: that is to say, while steps c-e arerepeated, production both of the injection-moulded part and also of thefront module takes place continuously, wherein the injection-mouldedpart is integrated in the front module. It is possible in particular torealize a mass production process in this way.

The transfer of the injection-moulded part into the second cavity andthe withdrawal of the front module from the second cavity may berealized for example using corresponding robots.

According to a further embodiment of the invention, theinjection-moulded part is encapsulated by injection moulding by thefirst plastic.

These and other aspects of the disclosed subject matter, as well asadditional novel features, will be apparent from the descriptionprovided herein. The intent of this summary is not to be a comprehensivedescription of the claimed subject matter, but rather to provide a shortoverview of some of the subject matter's functionality. Other systems,methods, features and advantages here provided will become apparent toone with skill in the art upon examination of the following FIGUREs anddetailed description. It is intended that all such additional systems,methods, features and advantages that are included within thisdescription, be within the scope of any claims filed later.

BRIEF DESCRIPTION OF THE FIGURES

Preferred embodiments of the invention will be explained in more detailbelow with reference to the drawings, in which:

FIG. 1 shows a schematic view of a motor vehicle having a front module,

FIG. 2 shows a schematic view of a front module,

FIG. 3 shows a schematic view of a front module,

FIG. 4 shows a schematic illustration of method steps for producing afront module as described above.

DETAILED DESCRIPTION Of ILLUSTRATIVE EMBODIMENTS

Below, elements which correspond to one another in the embodiments beloware denoted by the same reference numerals.

FIG. 1 shows a schematic view of a motor vehicle 100 having a frontmodule 108. The motor vehicle 100 has a body which has inter alia amudguard support 102 and an engine support 104.

For the fastening of the front module 108, it has longitudinal supportplates 110. Said longitudinal support plates 110 may for example bescrewed, as sketched in FIG. 1, or fastened generally to the enginesupport 104.

Also shown in FIG. 1 is a receptacle 106 for a lock for a bonnet of themotor vehicle 100. This will however be discussed in detail furtherbelow with reference to FIG. 3.

FIG. 2 shows a schematic view of a front module 108. All the elements ofthe front module 108 shown in FIG. 2 are formed in one piece with oneanother and consist exclusively of plastic. The front module 108 has atrapezoidal shape with two horizontal support elements 200 and 202 whichare spaced apart from one another and two vertical support elements 204which are spaced apart from one another. The upper horizontal supportelement 200 and the vertical support elements 204 are connected to oneanother by transverse struts 206. Here, the transverse struts 206consist of a plastic material which has a higher strength than theplastic material used for the support elements 200, 202 and 204.

The front module 108 also has two longitudinal support plates 110. Saidlongitudinal support plates 110 are arranged on the vertical supportelements 204 and serve, as described above, for fastening the frontmodule to a vehicle body (cf. FIG. 1). Here, the longitudinal supportplates 110 are arranged on the vertical support elements 204 at thelevel of the connection points between the respective vertical supportelements 204 and the transverse struts 206.

FIG. 3 shows a further embodiment of a front module 108 in a schematicillustration. In the same way as the front module described with regardto FIG. 2, the front module 108 in FIG. 3 also has a trapezoidal shape,wherein all of the elements illustrated in FIG. 3 are formed in onepiece with one another and consist exclusively of plastic, that is tosay in particular do not have metal reinforcements. In contrast to FIG.2, the upper horizontal support element 200 and the vertical supportelements 204 have different sections. With regard to the support element200, in section 302 between the connection points of the transversestruts 206 to the upper horizontal support element 200, use is made of aplastic which has the same material as that used for the transversestruts 206. The vertical support elements 204 have a region 304, whereinsaid region 304 is formed between the areal connection points(connection sections) of the respective vertical support elements 204and the longitudinal support plates 110. Said regions 304 are alsoproduced from the high-strength plastic material used for the transversestruts 206.

The front module 108 therefore consists, overall, of two plasticcomponents, specifically a high-strength plastic component for theregions 304 and 302 and the transverse struts, and also a plasticcomponent of lower hardness for the other support elements 200, 202 and204.

If for example high forces now act on the region 302, no deformationtakes place in said region and said forces are dissipated in aneffective manner via the transverse struts 206 and the region 304 to thelongitudinal support plates 110.

Also indicated in FIG. 3 are cutouts 300 which serve for the leadthrough of fastening means for fixing the longitudinal support plates onthe vehicle body (cf. FIG. 1). It is however pointed out that parts ofthe front module 108 may have further cutouts, for example also with anintegrated plastic thread. If such cutouts are provided on high-strengthregions of the front module 108, these may be used for receivingfastening means for the retention of further vehicle elements.Conceivable here would be the retention of for example different fluidcontainers such as containers for washer fluids, brake fluids or thelike.

Also shown in FIG. 3 is a receptacle 306 with cutouts 308. Saidreceptacle 306 serves for receiving and fastening a lock of a bonnet.The lock can be fixed to the front module 108 via the cutouts 308. Sincethe receptacle 306 is situated in the high-strength region 302 of thefront module 108, it is ensured that forces acting on the front module108 for example during the closure of the bonnet do not lead to adeformation of the front module 108. It is pointed out here that boththe region 302 and also the receptacle 306 are illustrated on an overdimensioned scale in FIG. 3. This however serves merely for illustrativepurposes. In reality, said regions will be significantly narrower so asto ensure that, to the sides of said regions, forces acting on thesupport element 200 can lead to a targeted deformation of the supportelement. As described above, this serves for example for pedestrianprotection. It is nevertheless possible in a cheap manner to provide alightweight and highly stable front module.

FIG. 4 schematically shows different steps of a method for producing afront module as described above in a two-component injection-mouldingprocess. Firstly, in step 400, an injection moulding device is providedwhich has two different injection moulding components 414 and 416 whichare spatially separate from one another. Not visible here are a firstand a second cavity of the injection moulding components 414 and 416.

Here, the method proceeds from the state in which an injection-mouldedpart 408 composed of a high-strength plastic and a front module,composed of a high-strength plastic 410 and a plastic of lower strength412, have already been produced in a cyclic fashion.

In step 402, the injection-moulded part 408 is now withdrawn from thefirst cavity, which can now be seen, and inserted into the second cavity420 of the injection moulding element 416. The finished front module 108comprising the high-strength plastic 410 and the plastic of lowerstrength 412 has previously been withdrawn from the second cavity420—said front module can now be used for example for installation in amotor vehicle.

In a step 404, the withdrawn injection-moulded part 408 is now insertedinto the cavity 420. As a result, in step 404, in the injection mouldingelement 414 there is an empty cavity 418 and in the injection mouldingelement 416 there is a cavity 420 which is partially filled by theinjection-moulded part 408.

In step 406, the method returns to the state denoted by the referencenumeral 400, in which the cavity 418 is filled with the high-strengthplastic and the cavity 420 is filled with the plastic of lower strength.As a result, a new injection-moulded part 408 is created in the element414, and a new front module 308 is created in the element 416. Themethod then continuous cyclically with steps 402 and 404.

LIST OF REFERENCE NUMERALS

100 Motor vehicle

102 Mudguard support

104 Engine support

106 Lock receptacle

108 Front module

110 Longitudinal support plate

200 Upper horizontal support element

202 Lower horizontal support element

204 Vertical support element

206 Transverse strut

300 Cutout

302 Reinforced region

304 Reinforced region

306 Lock receptacle

308 Cutout

400 Step

402 Step

404 Step

406 Step

408 Injection-moulded part

410 Injection-moulded part

412 Carrier element

414 Injection moulding element

416 Injection moulding element

418 Cavity

420 Cavity

What is claimed is:
 1. A two-component injection-molding method forproducing a front module for a motor vehicle, the method comprising thefollowing steps: a) providing an injection-molding device having a firstcavity and a second cavity; b) injecting a second plastic into the firstcavity thus obtaining an injection-molded part; c) transferring theinjection-molded part into the second cavity; d) injecting the secondplastic into the first cavity thus obtaining a further injection-moldedpart, and injecting a first plastic into the second cavity thusobtaining the front module; e) withdrawing the front module from thesecond cavity; and f) repeating steps c) to e).
 2. The method of claim1, wherein steps c) and e) are realized using corresponding robots. 3.The method of claim 1, wherein the injection-molded part is encapsulatedby injection molding by the first plastic.